采用柱层析分离与富集虫草素研究

以反相高效液相色谱全程监控虫草提取物中虫草素含量变化情况。研究结果表明,乙醇沉淀物中虫草素占总量的2%,乙醇上清液中虫草素含量占总量的98%,确定乙醇上清液可以作为样品;采用硅胶柱层析可以高效率地分离和富集虫草素。经硅胶柱层析,虫草素相对含量从1.40‰提高到20.89‰,为富集前的15倍;虫草素的硅胶色谱柱的最佳溶剂系统为,氯仿∶乙酸乙酯∶异丙醇∶水=400∶100∶300∶24,每10 mL流动相中加入2滴氨水;此法可以作为大量制备高纯度虫草素的产业化技术。     

烯效唑的色谱分析方法

烯效唑（Uniconazole）是20世纪80年代初13本住友公司推出的一种高效植物生长调节剂。能够提高水稻、小麦等作物有效分蘖率、同时提高植物的抗逆性阻引,增强机体免疫能力,广泛应用于果树、水稻、小麦等大田作物“有机农业”的“优质生产”。     

Venus lower atmospheric composition: analysis by gas chromatography

The first gas chromatographic analysis of the lower atmosphere of Venus is reported. Three atmospheric samples were analyzed. The third of these samples showed carbon dioxide (96.4 percent), molecular nitrogen (3.41 percent), water vapor (0.135 percent), molecular oxygen [69.3 parts per million (ppm)], argon (18.6 ppm), neon (4.31 ppm), and sulfuir dioxide (186 ppm). The amounts of water vapor and sulfur dioxide detected are roughly compatible with the requirements of greenhouse models of the high surface temperature of Venus. The large positive gradient of sulfur dioxide, molecular oxygen, and water vapor from the clould tops to their bottoms, as implied by Earth-based observations and these resuilts, gives added support for the presence of major quantities of aqueous sulfuric acid in the clouds. A comparison of the inventory of inert gases found in the atmospheres of Venus, Earth, and Mars suggests that these components are due to outgassing from the planetary interiors.     

葡萄叶面肥富硒特性及可溶态硒分布研究

探讨了叶面喷施氨基酸硒肥对富硒夏黑葡萄的应用效果,考察其富硒特性及可溶态硒的分布规律.结果表明,富硒最佳硒液浓度为250 mg/kg,效果明显;从夏黑葡萄生长绽叶期就开始定期喷施叶面硒肥,可显著改善叶片质量,有助于葡萄有机态硒的富集,葡萄硒含量最高达138μg/kg;葡萄富硒时期与富硒效果呈正相关关系(R2=0.959...     

铁改性微米竹炭处理农村低浓度磷污水的技术优化

为解决农村含低浓度磷污水缺乏深度处理、竹炭去除水中磷时粒径（PZ）较大、起始浓度（C₀）和投加量配比（dosing ratio,DR）高、处理接触时间（t）长等问题,将常规尺寸竹炭加工到微米范畴（0.45~75 µm）并进行铁改性,制备铁改性微米竹炭（MBC-Fe）;采用红外光谱、扫描电镜等表征MBC-Fe理化性质,模拟MBC-Fe吸附水中低浓度水平磷的吸附等温线模型;优化吸附条件后,应用MBC-Fe吸附去除农村含低浓度磷污水。结果显示：改性后的竹炭微孔体积增大,表面官能团发生变化;吸附等温线可回归Brunauer-Emmett-Teller （BET）模型;针对C₀ = 0.5 ~ 1.5 mg·L ^-1的低水平含磷水,优化的MBC-Fe处理条件是在投加量配比DR = 1:200（g:mL）,接触处理时间t = 0.25 ~ 0.5 h时,去除率可达90.0% ~ 96.7 %,磷残留低至0.05 mg·L ^-1;当C₀ = 0.51 ~ 0.58 mg·L ^-1时,DR最低为1:1 000 （g:mL）, 接触时间0.5 h,去除率可达60.26% ~ 71.02 %,处理后可达到Ⅲ类地表水的含磷要求。     

Radiometric analysis of tritiated organic compounds by means of vapor phase chromatography

An analytical method, involving the gas chromatographic separation and the quantitative measurement of tritiated volatile compounds, was studied. The method has been successfully employed to detect traces of carrier-free tritiated substances.     

Marihuana: identification of cannabinoids by centrifugal chromatography

Components in extracts of marihuana and hashish have been identified by a chromatographic technique in which centrifugal force is used to accelerate the migration of samples through columns of densely packed microparticulate gel. Rapid qualitative analysis and an estimate of the amounts of cannabinoids present was achieved.     

Pesticide mobility: determination by soil thin-layer chromatography

Pesticide movement was evaluated by the comparison of R(F) values on thin layers of soils. Results from the new technique correlated well with existing information on pesticide movement, facilitating the grouping of pesticides into classes on the basis of mobility. Thin-layer chromatography may have broad applicability in soils research.     

Plasminogen: purification from human plasma by affinity chromatography

Plasminogen was prepared from human plasma by affinity chromatography on L-lysine-substituted Sepharose. Thirty milligrams of plasminogen, with a specific activity of 100 caseinolytic units (Committee on Thrombolytic Agents) per milligram of nitrogen, were obtained from 340 milliliters of plasma. This corresponds to over 200-fold purification from plasma. Disc-gel electrophoresis at pH 8.3 indicated seven distinct bands, all of which contained activity.     

气相色谱法测定水果中辛硫磷的残留

采用分散基质萃取前处理方法,利用大口径毛细管柱(15m×530μm×0.88/μm)进行水果中辛硫磷残留的气相色谱法测定,并在4家农业部质检中心进行试验验证.结果表明,该方法精密度高(相对相差1.6%～10.9%),准确度好(添加回收率93%～107.8%);测定方法的重复性与再现性好,科克伦检验统计值0.0050～0.7963,格拉布斯检验统计值0.9801～1.4802,狄克逊检验统计值0.1250～0.8172;该方法操作简单快速,能够满足水果辛硫磷残留分析的要求.     

HPLC法快速测水产品中游离芳香族氨基酸含量的研究

建立了水产品中3种游离芳香族氨基酸含量的HPLC测定方法。试验确定了流动相的最佳pH、流速及浓度,并评价了方法的准确度、精密度和检测限。采用5%高氯酸溶液提取,用KOH溶液中和后进行HPLC分析。采用Waters Atlantis T3 C18（4.6×250 mm,5 μm）色谱柱分离,以15%甲醇-85%磷酸盐溶液为流动相,用磷酸调pH为6.0;色谱条件流速：0.9 mL/min;柱温：27 ℃;检测波长：256.7 nm;12 min内完成测定。结果表明：Tyr、Phe、Trp分别在6～500 μg/mL、30～1 000 μg/mL和3～250 μg/mL范围内有良好的线性关系,其线性相关系数（R²）在0.998 6～0.999 5之间。三者的检测限分别为2 μg/mL、10 μg/mL、1 μg/mL,加标回收率在88.0%～105.2%之间。方法操作简便且定性可靠、定量准确。     

Acetylcholine: release from neural tissue and identification by pyrolysis--gas chromatography

Gas chromatographic analysis showed acetylcholine to be the only choline ester released from innervated longitudinal muscle of the guinea pigileum by electrical stimulation. The amount of acetylcholine measured by gas chromatography agreed almost exactly with that measured by bioassay. Denervated longitudinal muscle produced no acetylcholine, and treatment of the muscle with tetrodotoxin markedly reduced acetylcholine output. The method permits the recovery and quantitation of amounts of acetylcholine as low as 5 nanograms in 5 milliliters of tissue perfusates.     

Systematic evolution of ligands by exponential enrichment: RNA ligands to bacteriophage T4 DNA polymerase

High-affinity nucleic acid ligands for a protein were isolated by a procedure that depends on alternate cycles of ligand selection from pools of variant sequences and amplification of the bound species. Multiple rounds exponentially enrich the population for the highest affinity species that can be clonally isolated and characterized. In particular one eight-base region of an RNA that interacts with the T4 DNA polymerase was chosen and randomized. Two different sequences were selected by this procedure from the calculated pool of 65,536 species. One is the wild-type sequence found in the bacteriophage mRNA; one is varied from wild type at four positions. The binding constants of these two RNA's to T4 DNA polymerase are equivalent. These protocols with minimal modification can yield high-affinity ligands for any protein that binds nucleic acids as part of its function; high-affinity ligands could conceivably be developed for any target molecule.     

QuEChERS前处理-气相色谱仪检测火龙果中的多种农药残留

通过简便高效的前处理方法—QuEChERS(Quick,easy,cheap,effective,rugged and safe)处理样品,使用气相色谱-电子捕获检测器对火龙果(Hylocereus undulatus Britt)中百菌清、三唑酮、氟虫腈、腐霉利、硫丹、联苯菊酯、甲氰菊酯、氯氟氰菊酯、哒螨灵、氟氯氰菊酯、氯氰菊酯、氰戊菊酯和溴氰菊酯等13种农药的残留量进行了检测,并与一些常规提取和固相萃取小柱(Solid phase extraction,SPE)净化方法进行了对比.结果表明:13种农药的检出限为0.009~0.400 ng/g,加标回收率在81.1%~108.0%之间,相对标准偏差为6.6%~17.0%,不同提取和净化方法间的加标回收率相差不大,SPE净化相对标准偏差相对要大.此方法有机溶剂用量少,选择性强,准确度高,灵敏度和精密度均符合要求,适合只配备气相色谱仪的基层试验室快速检测火龙果中常见农药残留.     

HPLC法同时测定加味四妙颗粒中6种成分

目的建立适合紫花苜蓿(Medicago sativa L.)叶片叶黄素循环组分：紫黄质(V)、环氧玉米黄质(A)和玉米黄质(Z)含量测定的方法。方法采用高效液相色谱(HPLC)法对紫花苜蓿叶片叶黄素循环的3个组分进行了测定,并对试验方法进行了验证。结果V、A和Z三个组分的标准品在3~100 μg/mL范围内均与峰面积呈良好的线性关系,相关系数分别为r=0.999 49、r=0.999 61和r=0.999 60,精密度试验(n=5)的RSD分别为0.96%、0.39%和0.87%,稳定性试验(n=7)的RSD值分别为3.33%、1.42%和1.86%,重现性试验(n=5)的RSD分别为0.48%、3.98%和2.59%,平均回收率(n=3)分别为99.55%、96.04%和94.08%,RSD分别为0.96%、1.38%和0.51%。结论HPLC法适于紫花苜蓿叶片叶黄素循环组分V、A和Z含量测定,该方法精密度高、重复性和稳定性好,回收率高。     

利用色谱聚焦和离子交换色谱快速分离分析薏苡38ku抗真菌蛋白

联合利用色谱聚焦和离子交换色谱对薏苡种子抗真菌蛋白进行了快速分离分析,首次发现一种新的薏苡抗真菌蛋白。该蛋白经SDS-PAGE检测相对分子质量在38左右,利用胶内酶切和MALDI-TOF-MS完成了肽谱分析,并进行了数据库搜索。     

瘤胃发酵液挥发性脂肪酸的气相色谱分析方法

以藏羊瘤胃发酵液为样品,选用2-乙基丁酸(2EB)为内标物,采用毛细管气相色谱法测定了瘤胃发酵液中的有机酸含量.结果表明,柱温180℃,柱压90 kPa时,可以有效分离乙酸、丙酸和丁酸,其回收率分别为96.7%、96.7%和96.4%.0.67μL藏羊发酵液中,乙酸、丙酸、丁酸的浓度分别为(36.5±1.12)mol/L(、8.55±0.92)mol/L和(4.34±0.81)mol/L.气相色谱法具有操作简便、快速、准确的优点,是测定反刍动物瘤胃发酵液挥发性脂肪酸较为理想的方法.     

广佛手多糖的分离纯化与相关成分的气相色谱分析

目的：分离与纯化广佛手中提取到的水溶性粗多糖．并分析其相关化学成分。方法：广佛手经醚和醇提后的药渣用热水提取．乙醇沉淀,Sevag法去蛋白后,逆向流水透析得多糖精品。用气相色谱法对其化学成分进行分析。结果：分离得到的水溶性多糖为单一多糖．无核酸和蛋白吸收．显示多糖类特征吸收峰。证实广佛手多糖是由D-木糖、D-甘露糖、D-葡萄糖、D-半乳糖和L-鼠李糖组成。结论：广佛手多糖为杂多糖。